a) you need to have the seed of having an open mind, that can help you later on. If you learnt to have a closed mind, then it's a fortress new ideas can't come in.
b) There is a upper limit of mixing proportions, above which the incoming mass of people is just too high, they stick together, and don't change / mix up with the existing population. This invasion is too big, too fast, for possible integration.
a) you need to have the seed of having an open mind, that can help you later on. If you learnt to have a closed mind, then it's a fortress new ideas can't come in.
b) There is a upper limit of mixing proportions, above which the incoming mass of people is just too high, they stick together, and don't change / mix up with the existing population. This invasion is too big, too fast, for possible integration.